remove concept of tour category and use only tour primary purpose

[bstabler]

trafficstars

For example, tour category school + person type results in different tour primary purposes --> K-8, high school, university. It would probably be better to only use tour primary purpose in the Python code so the special knowledge about the interaction of person type and school tours can be removed. This would make the code more generic and reusable. The example configuration would need to be updated as well.